/**
 * This jQuery plugin displays pagination links inside the selected elements.
 *
 * @author Gabriel Birke (birke *at* d-scribe *dot* de)
 * @version 1.2
 * @param {int} maxentries Number of entries to paginate
 * @param {Object} opts Several options (see README for documentation)
 * @return {Object} jQuery Object
 */
define(function(require, exports, module) {
    var $ = require("jquery");
    require("./pagination.css");

    $.fn.pagination = function(maxentries, opts) {
        opts = $.extend({
            items_per_page: 10,
            num_display_entries: 10,
            current_page: 0,
            num_edge_entries: 0,
            link_to: "javascript:void(0)",
            prev_text: "<i></i>",
            next_text: "<i></i>",
            ellipse_text: "...",
            prev_show_always: true,
            next_show_always: true,
            show_page_size_selection: false,
            callback: function() {
                return false;
            }
        }, opts || {});

        return this.each(function() {
            /**
             * 计算最大分页显示数目
             */
            function numPages() {
                return Math.ceil(maxentries / opts.items_per_page);
            }

            /**
             * 极端分页的起始和结束点，这取决于current_page 和 num_display_entries.
             * @返回 {数组(Array)}
             */
            function getInterval() {
                var ne_half = Math.ceil(opts.num_display_entries / 2);
                var np = numPages();
                var upper_limit = np - opts.num_display_entries;
                var start = current_page > ne_half ? Math.max(Math.min(current_page - ne_half, upper_limit), 0) : 0;
                var end = current_page > ne_half ? Math.min(current_page + ne_half, np) : Math.min(opts.num_display_entries, np);
                return [start, end];
            }

            /**
             * 分页链接事件处理函数
             * @参数 {int} page_id 为新页码
             */
            function pageSelected(page_id, evt) {
                current_page = page_id;
                drawLinks();
                var continuePropagation = opts.callback(page_id + 1, panel);
                if (!continuePropagation) {
                    if (evt.stopPropagation) {
                        evt.stopPropagation();
                    }
                    else {
                        evt.cancelBubble = true;
                    }
                }
                return continuePropagation;
            }

            /**
             * 此函数将分页链接插入到容器元素中
             */
            function drawLinks() {
                panel.empty();
                var interval = getInterval();
                var np = numPages();

                createPage(panel,np);
                var panelCon = panel.find('.pagination-con');

                // 这个辅助函数返回一个处理函数调用有着正确page_id的pageSelected。
                var getClickHandler = function(page_id) {
                    return function(evt) {
                        return pageSelected(page_id, evt);
                    }
                }

                //辅助函数用来产生一个单链接(如果不是当前页则产生span标签)
                var appendItem = function(page_id, appendopts) {
                    page_id = page_id < 0 ? 0 : (page_id < np ? page_id : np - 1); // 规范page id值
                    appendopts = $.extend({text: page_id + 1, classes: ""}, appendopts || {});
                    if (page_id == current_page) {
                        var lnk = $("<span class='current'>" + (appendopts.text) + "</span>");
                    } else {
                        var lnk = $("<a>" + (appendopts.text) + "</a>")
                                .bind("click", getClickHandler(page_id))
                                .attr('href', opts.link_to.replace(/__id__/, page_id));
                    }
                    if (appendopts.classes) {
                        lnk.addClass(appendopts.classes);
                    }
                    panelCon.append(lnk);
                }

                if (maxentries === 0) {
                    // 如果记录数为零，不显示分页
                    return;
                }

                // 产生"Previous"-链接
                if (opts.prev_text && (current_page > 0 || opts.prev_show_always)) {
                    appendItem(current_page - 1, {text: opts.prev_text, classes: "prev"});
                }
                // 产生起始点
                if (interval[0] > 0 && opts.num_edge_entries > 0)
                {
                    var end = Math.min(opts.num_edge_entries, interval[0]);
                    for (var i = 0; i < end; i++) {
                        appendItem(i);
                    }
                    if (opts.num_edge_entries < interval[0] && opts.ellipse_text)
                    {
                        $("<span>" + opts.ellipse_text + "</span>").appendTo(panelCon);
                    }
                }
                // 产生内部的些链接
                for (var i = interval[0]; i < interval[1]; i++) {
                    appendItem(i);
                }
                // 产生结束点
                if (interval[1] < np && opts.num_edge_entries > 0)
                {
                    if (np - opts.num_edge_entries > interval[1] && opts.ellipse_text)
                    {
                        $("<span>" + opts.ellipse_text + "</span>").appendTo(panelCon);
                    }
                    var begin = Math.max(np - opts.num_edge_entries, interval[1]);
                    for (var i = begin; i < np; i++) {
                        appendItem(i);
                    }

                }
                // 产生 "Next"-链接
                if (opts.next_text && (current_page < np - 1 || opts.next_show_always)) {
                    appendItem(current_page + 1, {text: opts.next_text, classes: "next"});
                }
            }

            // 创建分页左侧内容
            function createTotle(totleData){
                var str = '';
                str +='<span class="fl text-indent">共计 <span class="c-orange">'+ totleData +'</span> 条记录</span>';
                return str;
            }
            // 创建分页右侧内容
            function createRight(totlePage){
                var str = '';
                str +='<span class="fr">共计 <span class="c-orange">'+ totlePage +'</span> 页，到第<input type="text" class="pagination-input">页</span>';
                return str;
            }

            // 创建每页记录数选择
            function createPageSize() {
                var pageSizeList = {
                    '10': 10,
                    '20': 20,
                    '50': 50,
                    '100': 100
                };
                pageSizeList[opts.items_per_page.toString()] = opts.items_per_page;

                var html = '';
                html += '<div class="fl" style="margin-left: 10px; margin-right: 5px;">每页</div>';
                html += '<div class="fl" style="width: 60px;">';
                html += '   <div class="select">';
                html += '      <span class="select-border js-select-pagination">';
                html += '          <input class="select-text" type="text" readonly value="' + opts.items_per_page + '" />';
                html += '          <span class="select-icon"><i class="select-icon-arrow"></i></span>';
                html += '      </span>';
                html += '      <div class="select-sub">';
                for (var size in pageSizeList) {
                    if (pageSizeList.hasOwnProperty(size)) {
                        html += '          <a href="javascript:void(0);">' + size + '</a>';
                    }
                }
                html += '      </div>';
                html += '   </div>';
                html += '</div>';
                html += '<div class="fl" style="margin-left: 5px;">条</div>';
                return html;
            }

            var fnDocumentClick;
            // 创建整体分页内容
            function createPage(obj,totlePage){
                // 创建左侧数据内容
                obj.append(createTotle(maxentries));
                if (opts.show_page_size_selection) {
                    obj.append(createPageSize());

                    var select = obj.find('.select');
                    var inputBox = obj.find('.js-select-pagination');
                    var selectInput = inputBox.find('input');
                    inputBox.on("click", function (e) {
                        if (select.hasClass('select-on')) {
                            select.removeClass("select-on");
                            $(document).off('click', onDocumentClick);
                        } else {
                            select.addClass("select-on");
                            $(document).click(onDocumentClick);
                        }
                    });

                    select.on('click', 'a', function (e) {
                        var pageSize = $(e.target).text();
                        selectInput.val(pageSize);
                        setTimeout(function () {
                            opts.callback(1, panel, pageSize);
                        }, 0);
                    });

                    fnDocumentClick = function (target) {
                        if (!isOrHas(inputBox[0], target)) {
                            // 如果触发冒泡的元素不在控件元素之内，则将弹出框收起
                            select.removeClass("select-on");
                            $(document).off('click', onDocumentClick);
                        }
                    };
                }

                if (maxentries === 0) {
                    // 如果记录数为零，不显示分页
                    return;
                }

                if(totlePage > 1){
                    // 创建右侧数据内容
                    obj.append(createRight(totlePage));
                    var input = obj.find('.pagination-input');
                    // 给输入框绑定事件
                    input.on("keyup",function(){
                        var val = $(this).val();
                        $(this).val(val.replace(/[^\d]/g,''));
                    });
                        //回车跳转到输入的页面
                    input.on("keypress",function (e) {
                        if (e.keyCode == 0x0A || e.keyCode == 0x0D) {
                            var val = $(this).val();
                            if ($.trim(val)) {
                                val = Number(val) > totlePage ? totlePage : Number(val);
                                pageSelected(val - 1,e);
                                e.preventDefault();
                            }
                        }
                    });
                }
                obj.append('<span class="pagination-con fr"></span');
            }

            function isOrHas(container, target) {
                return $.contains(container, target) || container === target;
            }

            //点击桌面隐藏弹层
            function onDocumentClick(e) {
                var target = e.target;
                fnDocumentClick(target);
            }


            //从选项中提取current_page
            var current_page = opts.current_page;
            //创建一个显示条数和每页显示条数值
            if (typeof maxentries == 'string') {
                maxentries = parseInt(maxentries);
            }
            maxentries = (!maxentries || maxentries < 0) ? 0 : maxentries;
            opts.items_per_page = (!opts.items_per_page || opts.items_per_page < 0) ? 1 : opts.items_per_page;
            //存储DOM元素，以方便从所有的内部结构中获取
            var panel = $(this);
            
            // 获得附加功能的元素
            this.selectPage = function(page_id) {
                pageSelected(page_id);
            }
            this.prevPage = function() {
                if (current_page > 0) {
                    pageSelected(current_page - 1);
                    return true;
                }
                else {
                    return false;
                }
            }
            this.nextPage = function() {
                if (current_page < numPages() - 1) {
                    pageSelected(current_page + 1);
                    return true;
                }
                else {
                    return false;
                }
            }
            // 所有初始化完成，绘制链接
            drawLinks();
            // 回调函数
            //opts.callback(current_page, this);
        });
    }
});
